问题
I have regex for validating list of 50 ips comma-separated:
^(?:(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(?:,? ?)){1,50}$
list example:
10.10.10.1,127.0.0.1
now i need to support list, like this:
10.10.10.1,127.0.0.1-127.0.0.125
i try, to use subpatterns, but nothing happened
can somebody provide regex example for validating this string:
127.0.0.1-127.0.0.125
回答1:
You may use 2 things here: use the negated character class to match either , or -, and use a subrouting call to make sure your pattern stays of a reasonable size and the string cannot start with , or -:
^((?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))(?:[,-](?1)){0,49}$
See the regex demo
Details:
^- start of string((?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))- Group 1 capturing 1 IP address(?:[,-](?1)){0,49}- 0 to 49 (as the subpattern above already matched 1 IP, it will sum up to 50 all in all) sequences of:[,-]- a character class matching either,or-(?1)- the subroutine call that "repeats" Group 1 subpattern (unlike the backreference that matches the same value captured with a capturing group)
$- end of string
来源：https://stackoverflow.com/questions/40847544/regex-for-validating-ip-range-from-ip-list